Yes I have to agree with Dr Sylvia. Molar rotations, as with other tooth movements are not uncommon during orthodontic treatment. Your orthodontist would correct this eventually, as the treatment progresses. At 4 months into treatment, there is still much to be done so not to worry!
Do mention this to your orthodontist and share your queries with him/her as good communication is important for a successful outcome.
All the best!